A modular irrigation controller has a robust ground path with high conductivity that can accommodate lightning induced power surges on field valve wires and common wires that are connected to a plurality of station modules. Sensitive electronic components in the station modules are thereby protected from damage. The robust ground path extends from conductors on circuit boards within the station modules through captive mounting screws to a metallic backplane and then through metallic grounding brackets within a pedestal enclosing the modules and the backplane. The grounding brackets are in turn grounded to both an earth ground stake and to a ground wire associated with the incoming one hundred and ten volt AC power.